This invention relates to die casting equipment, and more particularly to a lubrication system for die casting equipment.
In die casting, molten metal is poured into a shot sleeve via a pour funnel. A plunger consisting of a plunger rod and a plunger tip is axially moved or extended into the shot sleeve to push the molten metal or "shot" into the die cast. It is necessary to both lubricate and cool the plunger due to the high temperatures, the presence of molten metal on the plunger tip and the plunger rod, and the friction between the plunger components and the shot sleeve.
In typical prior art plunger lubrication systems, a lubricant is sprayed from a pressurized lubrication source onto the plunger tip or into the shot sleeve via the pour funnel. This system has the disadvantages of being very messy since the sprayed lubricant has a tendency to scatter, and also is very inefficient and ineffective since the lubricant on the plunger rod and plunger tip may be unevenly distributed. Also, when the lubricant is sprayed into the shot sleeve and metal is poured into the sleeve, the lubricant has a tendency to burn, creating undesirable gases
Other prior art lubrication systems use complicated hydraulics or electronic timing mechanisms by which a lubricant is provided to the plunger components in timed relation to the position of the plunger. Such systems also typically require an additional source of high pressure to enable the lubricant to be transported to the outer surface of the plunger. In short, such systems are complicated and expensive since they require additional component parts.